By their design function, dryer exhaust conduits conduct substantial quantities of heated exhaust air from the dryer to an outside vent. The heated air contains significant amounts of water vapor and lint. In the case of natural gas fired dryers, carbon monoxide and other harmful combustion gases are routed out through the vent system as well.
The nature of the exhaust air in conjunction with the typical dryer vent installation can cause problems. Manufactures generally recommend that dryer installations be completed with metal or other rigid fixed conduit. This is an attempt to steer consumers away from the use of ribbed, flexible vinyl or foil tubing. While the familiar ribbed vinyl or foil tubing serves the intended purpose and has become the mainstay installation of "do-it-yourselfers" and discount appliance or other low cost appliance providers, it has drawbacks and dangers. These drawbacks fall into the areas of safety and efficiency.
Dryer exhaust vent installations constructed of vinyl or other soft tubing are inherently unsafe and inefficient because the flexible tubing lacks the intrinsic physical support of a rigid metal system and is a poor conductor of the heated, moisture and lint laden, dryer exhaust. The intrinsic flexibility of the soft tubing types allow for excessive bending and kinking that can cause significant airflow restrictions or blockages. This, is turn, allows for the unsafe build-up of lint, exhaust heat, and toxic fumes. At minimum, this condition lowers the efficiency of the dryer over time. At worst, it precipitates the numerous fires (between 11,000 to 14,000 by consumer protection group estimates) started by improper venting of home dryers each year. Even if the flexible tubing is routed with the proper consideration to avoid kinking or blockages, the tubing itself collects significant amounts of lint on its internal surface when combined with the water vapor content of the dryer exhaust air.
An additional safety concern is the materials used in these flexible tubing products. The vinyl tubing, by its nature, is combustible and the foil tubing is an inadequate construction of a thin, lightweight aluminum covering over a spring wound with heavy paper. Thereby, not only would either type of soft tubing fail to contain a conduit fire should one start but both types would offer an additional combustion source if the overheated lint buildup should ignite.
As mentioned above, efficiency of the dryer's venting system coincides with its safety considerations. The use of flexible tubing as well as the typical industry standard round pipe can limit the dryer's efficiency. The limitations fall generally in the area of the physical installation. Both the flexible tubing and the standard round pipe have space and placement considerations for the installer. The tubing and round pipe both have to be routed to accommodate their diameter and the radius turns necessary to complete the installation. This translates into the inability to place the dryer in close proximately to the wall. There must be a standoff area allowed for the tubing or pipe to the turned out away from the back of the dryer and a corresponding space accommodation where the vent turns into the wall. Certain installations are non-critical in this respect, locating a dryer in a wide open, basement of a single family home, for example. However, quite often space is at a premium for the installation of today's modern appliances. Dryers are often paired with washers in cramped first floor apartment closets or shoehorned into small pantry spaces. Even the wide open basements of a single family homes can no longer afford to waste space by placing a dryer well away from a back or side wall. Efficiency also is lost in the luxury of a dryer vent installation that uses great amounts of free space. The dryer should have the shortest, most direct route to the outside wall vent. This minimizes airflow losses to lint buildup and reduces the chance of occurrence of vent blockages.
Since the long term build up of lint particulate is of critical concern, it should also be noted that the typically flexible tubing installation is in one long singular piece that does not generally facilitate or encourage regular disassembly and cleaning by the consumer. This again causes concern as a fire hazard. This non-accessible, permanent type of installation also plagues the other typical rigid type of dryer vent conduits available today. The consumer is not predisposed to effect cleaning of the dryer vent after it is installed and enclosed.
Therefore, it is the design intention of the present invention to overcoming these shortcomings. The low profile dryer vent exhaust system provides a compact and efficient short route to the outside vent by utilizing a flattened profile for its exhaust conduit. This allows for a rigid, substantial ductwork system that turns tight and has minimal radii. A unique feature of the system provides the homeowner with access ports for periodic cleaning, inspection, and removal of lint buildup. The rigid metal construction eliminates the problems with conduit combustibility and significantly lowers the rate of lint build up.